1. Field of the Invention
The present disclosure relates to a tuned mass vibration damper for a drivetrain of a motor vehicle, for damping a vibration component of a rotational movement. Tuned mass vibration dampers can be used within the framework of starting elements in a hydrodynamic torque converter in a motor vehicle.
2. Detailed Description of Prior Art
In many starting elements, also referred to as starting clutches, tuned mass vibration dampers are used to damp rotational irregularities originating in an internal combustion engine. Torque shocks transmitted via the crankshaft to an input of a starting element of this type occur operationally in internal combustion engines due to energy being released in bursts. To keep these torque shocks away from an output of the starting element which is itself often coupled to an input of a transmission, or at least to damp them, vibration dampers can be used to damp these and other vibration components of the rotational movement of the crankshaft.
To this end, vibration dampers often have an oscillatory system or a system having the capability of temporarily storing energy by energy accumulators. Depending on the specific implementation of a corresponding vibration damper, spring elements or other energy accumulators can be used for this purpose.
In tuned mass vibration dampers, oscillating pendulum masses, also referred to as damper masses, are used to store energy spikes in a corresponding rotational movement. In contrast to many other vibration dampers in which the rotational movement to be transmitted and, therefore, the torque to be coupled into an input side of the vibration damper and coupled out again at the output side, tuned mass vibration dampers typically have only one connection by which they are coupled to the rotational movement to be transmitted. In other words, in tuned mass vibration dampers the spring elements, i.e., damper masses, are not typically arranged in the torque path. Rather, the connection of the tuned mass vibration damper serves to absorb the above-mentioned energy spikes and to deliver the buffered energy.
Currently, there are many additional requirements for tuned mass vibration dampers apart from the basic function of the tuned mass vibration damper, namely, to damp a vibration component of a rotational movement. For example, it should be possible to produce them as simply as possible. They should also utilize the total available installation space as efficiently as possible. Often, there is only a predetermined total installation space available for a starting element that must be shared by the individual components of the starting element. In mechanical systems for vibration damping, the size of a component often has an important influence on its function. However, in view of the limited available installation space, constraints may arise with respect to the most efficient possible utilization of the installation space available for the tuned mass vibration damper.
There are also efforts being made to construct a corresponding tuned mass vibration damper by the simplest possible technical means, and using as few resources as possible, and to integrate it in a corresponding starting element. Accordingly, in this respect also, there is a demand for the most efficient and simplest possible production of a tuned mass vibration damper, for which purpose a compromise could be made between use of material and the actual production resources expended on installation.
Due to the fact that corresponding damper masses used in tuned mass vibration dampers themselves execute oscillations in order to damp a vibration component of the rotational movement, it can possibly come about under certain operating conditions that the damper masses produce noises found annoying by the driver and the passengers of a vehicle in which the starting element is integrated, as well by other persons and passers-by. Depending on the specific implementation of a tuned mass vibration damper of this type, metallic noises, for example, can be produced which may occur, for example, during the starting of the engine or when switching it off.
During operation of a tuned mass vibration damper, centrifugal forces in particular also occur in addition to the weight force, which centrifugal forces act on the damper masses. Due to the centrifugal force brought about by the engine rotating speed, the damper masses, also referred to as weights, of a tuned mass vibration damper of this type are pressed radially outward. The centrifugal force depends on the speed, the center of gravity radius and the mass of the damper masses. In this connection, speed is the variable that is easily influenced during operation. When switching off the engine, for example, the engine speed decreases until the engine finally stops (0 rpm).
When switching off the engine, an engine speed is reached at which the magnitude of the weight force acting on the damper masses exceeds in that of the centrifugal forces acting on the damper masses. At this point, it may happen that the individual damper masses collide with one another and produce the annoying noises mentioned above.
Such noises can also be generated by the rollers on which the damper masses can be supported. When these rollers strike the stops in their path curves, this can also be accompanied by an annoying noise. Thus as a result of the momentum of the damper masses, a noise can be produced that is unaccustomed and therefore bothersome to the driver, the passengers of the vehicle, or other persons. Therefore, efforts are also made to reduce, minimize or possibly even completely eliminate occurrence of noises during operation of a tuned mass vibration damper.
Apart from starting elements such as can be used in a drivetrain of a motor vehicle, tuned mass vibration dampers can also be used in other rotating systems in which damping of a vibration component of the rotational movement is necessary or advisable. Examples can be found in the field of machine tool engineering as well as in other fields of machine building and automotive engineering in which corresponding rotational irregularities occur, or can occur, in a rotational movement.
DE 10 2011 004 443 A1 relates to a vibration damping device in a vehicle having a deflection mass support rotatable around a rotational axis and at least one deflection mass supported at the deflection mass support so as to be displaceable with respect to it. A deflection of the at least one deflection mass out of a basic relative position with respect to the deflection mass support changes a radial position of the at least one deflection mass with respect to the rotational axis. A restoring or return arrangement is associated with at least one deflection mass and exerts a force oriented in direction of its basic relative position on the deflection mass at least in a partial range of the deflecting movement of the relevant deflection masses.
DE 10 2011 100 895 A1 is directed to a centrifugal pendulum absorber, particularly in a drivetrain of a motor vehicle, with a pendulum flange that is rotatable around an axis of rotation and with a plurality of pendulum masses distributed along the circumference on both sides of the pendulum flange. Two axially opposed pendulum masses are connected to one another in each instance by connection elements extending through the pendulum flange to form pairs of pendulum masses. The pairs of pendulum masses are spaced apart from one another in circumferential direction. In order to achieve an elastic limiting of the pendulum masses without resorting to stop bumpers and cutouts made for the latter in the pendulum flange, an elastic limiting of a swiveling movement of the pendulum masses is implemented by an annular spring provided radially within the pendulum masses.